Prefabricated linear drainage channels, or trench drains, frequently are employed to collect and carry away surface water and other liquid materials from parking lots, factory floors, side walks, driveways and other surfaces. Typically, the drainage channels are constructed so as to have two side walls joined at their bottoms by bottom walls. The tops of the side walls are provided with ledges that support a grating. Normally, the drainage channel is positioned slightly lower than the surface from which water or some other liquid is to be collected and carried away. As a result, the surface water, or other liquid, flows to the top of the drainage channel, through the grating and down to the bottom of the drainage channel from where it is conveyed to a disposal site. It is usually the case that the drainage channels are fabricated in units of a length that allow the channels to be readily handled. At the same time, ordinarily, it is necessary to convey the collected surface waters a distance greater than the length of any individual unit. Consequently, the drainage units must be arranged end-to-end so that the surface water can be conveyed the requisite distance for appropriate disposition.
Typically, the drainage channels are installed in a trench that is created in the surface from which surface water is to be collected and carried away. The trench is wider and deeper than the width and height of the drainage channels which are arranged end-to-end in the trench at an appropriate height above the bottom of the trench. The drainage channels are supported in the trench in that fashion while a filler material such as concrete or asphalt is introduced into the open space between the trench and the drainage channels. Once the filler material has set or hardened and the drainage channels are fixed in place, the gratings are installed and the drainage channels can be placed into service.
A variety of devices and methods are known for the purpose of supporting the drainage channels in the trench while the filler material is introduced into the open space between the drainage channels and the trench. Several considerations that are relevant with respect to the implementation of any particular supporting device or method are as follows: (1) By not locating the supporting devices in the trench and fashioning the devices so as to be removable, they will not become embedded in the filler material when it hardens and can be reused. (2) The devices and methods, preferably, will allow the tops of the drainage channels to be readily set at any desired level so as to insure that surface water will flow into the drainage channels when they are put into service. (3) The supporting devices and methods will keep the drainage channels from floating and shifting under the influence of the filler material as it is introduced into the open space between the trench and the drainage channels. (4) The supporting devices and methods will be such that any tendency for the drainage channel side walls to collapse toward one another as a result of the pressure of the filler material will be minimized.